Connection insert

ABSTRACT

A connection insert includes a central adhesive supply channel and outlets which are perpendicular to the channel. The connection insert consists of a plurality of parts, and comprises an inner part provided with the adhesive supply channel and an outer sleeve that can be at least partially inserted into a borehole of a component.

BACKGROUND AND SUMMARY

The invention relates to a connection insert and more specifically to aconnection insert with adhesive supply channel.

This connection insert is used for the fastening of components toboards, these boards generally having a soft inner core and hard coverboards. These boards are generally called lightweight boards. Theconnection insert is provided with a central adhesive supply channel andwith outlets for the adhesive which are perpendicular to the channel. Ina construction, the above-mentioned board-shaped components are used,among other uses, for the production of furniture. The connectioninserts are used for guiding the adhesive such that it reaches theconnection inserts and the latter form a fixed connection with the fixedregions of the boards. However, it is also conceivable that the endregions of the connection inserts are inserted into boreholes orrecesses of the board-shaped components so that they support theadhesive connection.

It is a disadvantage of the previously known connection inserts that theguiding of the adhesive is not precisely defined, so that it frequentlyhappens that the adhesive does not arrive at the point where the actualadhesive connection is to take place. However, a precise guidance isrequired because adhesives are considered to be semi-fluidic; that is,their viscosity is relatively high.

It is an object of the disclosure to design a connection insert of theinitially described type such that a precise guidance of the injectedadhesive is ensured, so that the adhesive connections take place at thedefined locations.

This object is achieved in that the connection insert consists of aplurality of parts and comprises an inner part having the adhesivesupply channel and an outer sleeve enveloping the inner part.

The adhesive is placed in the connection insert by means of a suitabledevice from a front side. The outside surface of the inner part and theinside surface of the outer sleeve may be designed such that a targetedadhesive guidance is feasible. In particular, depending on the usage ofthe connection insert, the outer sleeve can be designed such thattargeted adhesive connections are achieved. Since it causes thedistribution of the adhesive, it could also be called a distributorsleeve or an adhesive guiding sleeve.

In the simplest construction, the connection insert consists exclusivelyof the inner part and the outer sleeve. An annular gap is arrangedbetween the inside surface of the outer sleeve and the outside surfaceof the inner part.

For reinforcing the adhesive connection between the connection insertand the adjacent component, for example, to a board, the inner part hasa head at least at one end, which head can at least partiallyform-lockingly and/or force-lockingly be inserted in a borehole or in arecess of the component. The connection of the head of the inner partwith the component can take place in a particularly simple manner. Thecircumferential surface of the head is profiled such that the raisedparts mold themselves into the material bounding the borehole or therecess. This becomes possible because the concerned components consistof wood or a wood-like material. The profiling of the circumferentialsurface can be formed by harpoon-type webs, so that the inner part canbe pressed in one direction into the borehole or into the recess, butthat a pulling-out in the opposite direction is possible only bydestroying the material parts bounding the borehole or the recess. Themutually spaced harpoon-type webs may be shaped in a surrounding mannerto the head of the inner part; they may also extend over certain partialregions of the circumference; or the may extend in the direction of thelongitudinal center axis of the inner part, so that an antitwistprotection is correspondingly provided in the last embodiment.

For gluing the head of the inner part to the surfaces bounding theborehole or the recess, the head of the inner part is equipped with atleast one, for example two diametrically opposite adhesive outletopening(s). The adhesive outlet opening or openings is/are expedientlydesigned in a slot shape as well as extending in the direction of thelongitudinal axis of the inner part.

In order to also permit the gluing-together over the entire length ofthe shaft of the inner part, the inner part has several mutually spacedcircumferential grooves on the circumferential surface. So that adhesivecan also penetrate into these circumferential grooves, the inner partoutside the head has at least one adhesive outlet opening, preferablywith two mutually diametrically opposite adhesive outlet openings.Through each adhesive outlet opening, the adhesive can then arrive inthe annular gap between the outside surface of the inner part and theinside surface of the outer sleeve. So that the adhesive can also arrivein the end regions of the shaft of the inner part, each adhesive outletopening is arranged in the central region of the shaft.

The adhesive can be pressed into the adhesive supply channel of theinner part only from a front side. So that the quantity of the adhesiveremaining in this channel is limited, the adhesive supply channel isdivided into two sections, and that only one section extends into theregion of the adhesive outlet openings. For securing the outer sleeve,the inner part is equipped with a locking ring on the side facing awayfrom the head. The locking ring is designed such that such a deformationtakes place as a result of the effect of a compression force. Thus, theouter sleeve can be placed upside down onto the inner part. In addition,a lateral distribution of the adhesive takes place. So that the adhesivecan be distributed over the entire length or height of the shaft of theinner part and also over the inside surface of the outer part, theinside surface of the outer sleeve is constructed as a profiling whichis formed of indentations and elevations extending in the longitudinaldirection. In other words, the elevations and indentations extendtransversely to the circumferential grooves of the shaft of the innerpart.

In addition, in the end region facing the head of the inner part, theouter sleeve is provided with several slots in order to facilitate thejoining or the snapping-together of the inner part with the outersleeve. Furthermore, when adhesive is supplied, the latter emerges fromthe slots, which has a positive influence on the adhesive connection.

The adhesive supply normally takes place under pressure. Particularlythe outer sleeve could be called an adhesive guiding element so that theadhesive is pressed into the end regions in a targeted manner. After areduction of the supply pressure, the adhesive could flow back into thecentral region of the outer sleeve. In order to prevent this, the outersleeve is equipped with flexible retaining elements for the adhesive onthe outside surface at least in the end regions. These retainingelements are designed such that they form a corresponding abutment. Theretaining elements may be arranged in different fashions. Thus, theyextend radially or tangentially with respect to the outside surface ofthe outer sleeve in the end regions facing the outside surface of theouter sleeve. Although it is sufficient for the retaining elements to bearranged in the end regions, in another embodiment, they are arrangedradially with respect to the longitudinal center axis of the outersleeve and extend over the entire length or almost the entire length ofthe outer sleeve. In this case, the lengths of the retaining elementsincrease from the center region to the end regions of the outer sleeve,for example in a continuous manner. As a result, analogously an outercontour is created relative to the longitudinal section, which can beconsidered to be concave. The retaining elements are expedientlyconstructed as bristles, strips or the like.

It is also provided that the adhesive supply channel has a sieve or aperforated plate in the end region. This proportions the adhesivequantity and prevents that impurities penetrate into the adhesive supplychannel. Depending on the usage, it may also be expedient to provide theouter sleeve with several openings, which are circular or have aconfiguration deviating from the circular shape.

The range of applications of the connection insert is diverse. Thus, theouter and the inner part each have a cup-shaped construction, and theconnection insert can be fixed to a furniture component or a furnitureleaf by generally known eccentric fitting.

The connection insert may be called a dowel in order to fasten fittingsor the like, for example, by a screw.

The connection insert will be explained in greater detail by means ofthe attached drawings.

BRIEF DISCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded as well as perspective view of the inner part andthe outer sleeve of a connection insert of the present disclosure as adetail;

FIG. 2 is a front view of the inner part;

FIG. 3 is a sectional view of the inner part;

FIG. 4 is a view of a first embodiment of a connection insert arrangedbetween two cover layers;

FIG. 5 is a view of a second embodiment of a connection insert arrangedbetween two cover layers;

FIG. 6 is a cut-away view of the connection insert arranged between twospaced cover layers of the boards;

FIG. 7 is a view of the connection insert according to the presentdisclosure in combination with an eccentric fitting;

FIGS. 8 to 10 are views of three different embodiments of the connectioninsert equipped with retaining elements; and

FIG. 11 is a sectional view of a connection insert according to anotherembodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The connection insert illustrated in FIGS. 1 to 7 consists of an innerpart 10, which will be explained in detail, and of an outer sleeve 12,which can be fitted onto a shaft 11 of the inner part 10 and will alsobe explained in detail. At one end, the inner part 10 is also equippedwith a head 13 whose circumferential surface is profiled. This profilingconsists of several harpoon-type webs 14, as illustrated particularly inFIGS. 2 and 3. The inner part 10 is provided with an adhesive supplychannel 15 consisting of two sections 15 a and 15 b. As illustratedparticularly in FIG. 3, the two sections 15 a, 15 b of the adhesivesupply channel 15 are mutually separated by a wall. In addition, thetube-shaped inner part 10 is provided with two mutually diametricallyopposite adhesive outlet openings 16, 17. These are designed as oblongholes and are arranged such that only adhesive can penetrate fromsection 15 a to the outside.

As shown in FIGS. 1 to 3, the shaft 11 of the inner part 10 also hasseveral circumferential grooves 18 on the exterior side and are spacedwith respect to one another. The figures also illustrate that the innerpart 10 is equipped with a locking ring 19 on the side situated oppositethe head 13. When the outer sleeve 12 fitted onto the shaft 11, thelocking ring extends beyond the outer sleeve and prevents sapartion ofthe inner part 10 and the outer sleeve 12. This outer sleeve 12 can bedeformed because of the form-elastic and material-elasticcharacteristics of plastic materials, so that the outer sleeve 12 can beplaced upside down onto the inner part 10.

As illustrated by FIGS. 1 and 2, in the region of the head 13, the innerpart 10 is also provided with two mutually diametrically opposite,slot-type openings 20 through which adhesive emerges for the gluing ofthe head 13 to the elements it is inserted into.

FIGS. 4 to 6 show the arrangements of a lightweight board with the coverlayers 21, 22 and a connection insert arranged in-between. For thispurpose, the outer sleeve 12 is pushed onto the shaft 11 of the innerpart 10. The adhesive can then be pressed into the section 15 a of theadhesive supply channel 15, penetrates the radial adhesive outletopenings 16, 17 and is then distributed into the annular gap 25 betweenthe inside surface of the outer sleeve 12 and the outside surface of theshaft 11. Slots arranged in an end region of the outer sleeve 12 ensurethe exiting of the adhesive which thereby comes in contact with thecover layers of the lightweight boards in a targeted manner. For lockingthe outer sleeve 12 with the shaft 11, the outer sleeve 12 is providedwith slots 23 extending in the longitudinal direction on the sideassigned to the head 13 of the inner part 10.

In the embodiment according FIG. 4, the locking ring 19 is supported onthe assigned surface of the cover layer 22, while, in the embodimentaccording to FIG. 5, the cover layer 22 is provided with a recess 24 inwhich the locking ring 19 engages. FIGS. 4 and 5 illustrate that theharpoon webs 14 of the head 13 pit or dig into the material of the coverlayer 21 bounding the borehole. In addition, the securing also takesplace by gluing.

FIG. 6 shows the arrangements according to FIGS. 4 and 5 in the cut-awaycondition. This figure illustrates that an annular gap 25 is formedbetween the outside surface of the shaft 11 and the inside surface ofthe outer sleeve 12, the adhesive running in this annular gap 25 andbeing deposited on the interior sides of the cover layers 21, 22.

FIG. 7 shows a variant for fixing a corner connection fitting in alightweight board. The inner part 10 and the outer sleeve 12 each have acup-shaped construction. The adhesive guidance is analogous to thedescriptions of FIGS. 1 to 6 and is not shown in detail. In addition,the bracing takes place by an eccentric fitting 26, which is generallyknown. Also, a dowel 27 is inserted in a borehole of a board 28 which,in turn, is fixed in another component 30.

FIGS. 8 to 10 show embodiments, in which retaining elements 29 in theform of bristles, strips or the like are placed on the outside surfaceof the outer sleeve 12. The figures show that the adhesive is pressed bypressure into the end regions of the outer sleeve 12. After thereduction of this pressure, the adhesive could flow back, although onlypartially and only by a relatively small amount. In order to preventthis, essentially radially extending retaining elements 29 are placed inthe end regions of the outer sleeve 12 in the embodiment according toFIG. 8. Also in the embodiment according to FIG. 9, the retainingelements 29 are fixed in the end regions. In this embodiment, at leastthe end regions facing the outside surface of the outer sleeve 12 extendtangentially or approximately tangentially.

In the embodiment according to FIG. 10, the retaining elements 29 areessentially distributed over the entire length and also over the entirecircumference of the outer sleeve 12. They are again disposed radiallywith respect to the longitudinal center axis of the outer sleeve 12.However, in a longitudinal sectional view, a concave shape of the outercontour is obtained because the lengths of the retaining elements 29increase continuously from the center region to the end regions. Theretaining elements 29 may be bristles consisting, for example, of aplastic material.

FIG. 11 shows an embodiment in which, in contrast to the previouslydescribed constructions, the effective length of the connection insertcan be changed.

This is achieved by an extension sleeve 31 which is telescopicallydisplaceably fitted over the outer sleeve 12. The remaining constructionof the connection insert according to FIG. 11 basically corresponds tothe previously described variants; that is, the above-mentioned outersleeve 12 is placed on the shaft 11 of an inner part 10 having anadhesive supply channel 15.

As mentioned above, the telescopically displaceable extension sleeve 31is pushed into this outer sleeve 12. The extension sleeve 31 can bedisplaced relative to the outer sleeve 12 in the axial direction of theentire arrangement, whereby the overall length of the connection insertcan be changed in a simple manner and can be adapted to differentthicknesses of lightweight boards.

At its free front-side end 32, the extension sleeve 31 is provided withaxially extending slots 33 through which adhesive can penetrate towardthe outside.

Deviating therefrom, the extension sleeve 31 may be provided withadhesive outlet boreholes in the front-side region. It is alsoconceivable to construct the face of the extension sleeve 31 in a wavyshape or to provide it with radial serrations in order to permit anexiting of adhesive.

The connection insert is not limited to the illustrated embodiments. Itis essential that the connection insert is constructed of several parts,preferably two parts, and is formed of the inner part 10 and the outersleeve 12. Furthermore, it is important that the guiding of the adhesiveis precisely defined by the adhesive supply channel 15, by the adhesiveoutlet openings 16, 17, by the radial grooves 18 and by the annular gap25.

1. A connection insert for a component comprising: an inner part havinga central adhesive supply channel therein and an outlet openingconnected to and disposed transverse to the supply channel; and aseparate outer sleeve concentric to the inner part which can be at leastpartially inserted into a borehole of the component; wherein the head ofthe inner part is profiled; and wherein the circumferential surface ofthe head has harpoon-type webs.
 2. Connection insert according to claim1, wherein the connection insert consists exclusively of the inner partand the outer sleeve.
 3. Connection insert according to claim 1, whereinthe inner part has a head at least on one end, which head can beinserted at least partially in one of form-lockingly and force-lockinglyin a borehole or a recess of a component.
 4. Connection insert accordingto claim 1, wherein, at the head, the harpoon-type webs are arranged ina surrounding manner, extending over partial regions or extending in thedirection of a longitudinal center axis of the inner part.
 5. Connectioninsert according to claim 1, wherein, on the circumferential surface,the inner part has several circumferential grooves extending in amutually spaced manner.
 6. A connection insert for a componentcomprising: an inner part having a central adhesive supply channeltherein and an outlet opening connected to and disposed transverse tothe supply channel; and a separate outer sleeve concentric to the innerpart which can be at least partially inserted into a borehole of thecomponent; wherein the inner part has a head at least on one end, whichhead can be inserted at least partially in one of form-lockingly andforce-lockingly in a borehole or a recess of a component; and whereinthe head of the inner part includes two diametrically mutually oppositeadhesive outlet openings.
 7. Connection insert according to claim 6,wherein the adhesive outlet openings are a slot shaped extending in anlongitudinal direction of the inner part.
 8. Connection insert accordingto claim 6, wherein spaced from the head, the inner part includes twomutually diametrically opposite adhesive outlet openings.
 9. Connectioninsert according to claim 8, wherein the adhesive outlet openings arearranged in the central region of a shaft of the inner part. 10.Connection insert according to claim 6, wherein on the side facing awayfrom the head, the inner part includes a locking ring.
 11. Connectioninsert according to claim 6, wherein an inside surface of the outersleeve is a profiling which is formed of indentations and elevationsextending in the longitudinal direction.
 12. Connection insert accordingto claim 6, wherein the outer sleeve includes several slots in an endregion facing the head of the inner part.
 13. A connection insert for acomponent comprising: an inner part having a central adhesive supplychannel therein and an outlet opening connected to and disposedtransverse to the supply channel; and a separate outer sleeve concentricto the inner part which can be at least partially inserted into aborehole of the component; and wherein the adhesive supply channel isdivided into two sections, and only one section extends into a region ofradially extending adhesive outlet openings.
 14. A connection insert fora component comprising: an inner part having a central adhesive supplychannel therein and an outlet opening connected to and disposedtransverse to the supply channel; and a separate outer sleeve concentricto the inner part which can be at least partially inserted into aborehole of the component; and wherein the adhesive supply channel iscovered by one of a sieve and a perforated plate.
 15. Connection insertaccording to claim 14, wherein the outer sleeve includes severalcircular openings or openings deviating from the circular shape.